Plating point assembly for electroplating racks



y 1952 E. LILES 2,595,681

PLATING POINT ASSEMBLY FOR ELECTROPLATING RACKS Filed May 18, 1949 v 2SHEETS-SHEET 1 5 fiZZXIZ for .7 'ZZ77Z67 Elzles a; orize s May 6, 19522,595,681

PLATING POINT ASSEMBLY FOR ELECTROPLATING RACKS Filed May 18, 1949 2SHEETS-SHEET 2 Patented May 6, 1952 UNITED STATES PATENT OFFICE PLATINGPOINT ASSEMBLY FOR .ELECTROPLATING RACKS 'Elmcr E. Liles, Harvard, Ill.

ApplicationMay 18, 1949, Serial No. 93,968

8 Claims. 1

This invention relates to a plating point assembly forelectroplatingracks,.and in particu- ,jacket is meant a covering which is not damagedby the acid or alkaline baths used in electroplating, and which is notsubject to electrochemical action.

The racks on which objects arehung for electrcplatingmust be of metal,and must be provided with plating points on which may be hung theobjectsbeing plated. Theracks, the points, and the objects being platedform one side of the electroplating circuit and are connected "to asource or electric current by a buss bar. Thus :they must be inmetal-to-metal contact. All of "the rack which is submerged in theplating bath,

lacquered by dipping into a primer, after which it must be baked forapproximately one-half hour. After it has been cooled, any blisters inthe lacquer must be removed and bare spots touched up. A second primingcoat is then applied which Ifurnishes the proper base for adherence ofthe final protective coating. Following the second priming coat, therack is baked for at least twenty minutes and preferably longer. The'final protective dielectric coating is a liquid which is in a tank atroom temperature. The rack, hot from the oven, is dipped into theprotective dielectric which adheres to it in a coating, the thickness ofwhich depends upon the temperature of the rack when it is immersed inthe coating material. After the rack has stood for about one-half hourto permitthe coating to set in a preliminary way, it must be baked at365 for a period of one to one and onehalf hours to finally set theprotective coating. Thus, it is seen that application 'of the protectivedielectric coating to an electroplating rack occupies upwards of half adays time, and involves a considerable amount of handling and use ofhigh temperature ovens.

Heretofore there has been no assembly by which the plating points couldbe removably secured in electric contact with the rack, and in which thecontact elements were covered by a protective dielectric material. Thepoints have commonly been welded or screwed to studs on' the rack, andthe entire assembly coated as described above. The points, especiallythose used for plating heavy parts such as automobile grilles andbumpers, are subject to breakage, and when a point broke it wasnecessary to take the entire rack out of service and strip the coatingtherefrom, weld, or screw on a new point, and recoat the rack andpoints.

The principal object of my invention, therefore, is to provide a sealedassembly inwhich a plating point may be secured, and in which a brokenpoint may be readily replaced without disturbing the protectivedielectric coating on the rack.

A further object is to provide such anassembly in which the parts areinexpensive and may be readily assembled.

Yet another object is to provide such an assembly in which the platingpoint is g ipped 'to prevent rotation.

The invention is illustrated in a preferred em bodiment in theaccompanying drawings in which:

Fig. 1 is a sectional view of an electroplating tank with a typical rackin place therein;

Fig. 2 is a section taken as indicated at the line 2-2 of Fig. l;

Fig. 3 is a section taken as indicated at, the line 33 of Fig. 2;

Fig. 4 is a vertical central sectional view of the core; Fig. 5 is asection taken as indicated at the line 5-5 of Fig. 2;

Fig. 6 is a side elevation, partially in section, of the bottom segmentof the protective dielectric shield means; and

Fig. 7 is a section taken as indicatedat the line 'l-l of Fig. 1.

Referring to the drawings in greater detail, an electroplating tank I 0is provided with a buss bar H which is connected to a source of electriccurrent (not shown). Hung from the buss bar II is an electroplatingrack, indicated generally at I2, which takes the form of a rectangularframe l3 with a hook l4 at its upper end by which it may be hung on thebuss bar. A plurality of electroplating point assemblies, indicatedgenerally at l5, are secured to the rack 12. As best seen in Fig. 7, allsubmerged portions of the electroplating rack are covered by aprotective dielectric coating I6.

As best seen in Figs. 2 and 4, each plating point assembly 15 comprisesahollow cylindrical metal core l1 having a flange l8 forming a base atits lower end. The upper surface of the base I8 is annularly grooved atl9. In securing the plating point assembly |5 to the rack I2, the baseI8 is preferably welded, brazed or soldered to the rack prior to theapplication of the protective dielectric coating l6, although any meansproviding firm metal-to-metal contact is satisfactory. A temporary capis placed over the core I1, and the dielectric coating is applied to therack and to the bases l8 of the plating point assemblies l5. The annulargroove I9 in the base l8 provides a footing for the coating |6 so thatthere is little tendency for the coating to slide or be pressed awayfrom the side wall of the core H when the assembly is completed.

The core I1 is transversely slotted at 20, and the upper portion of thecore I! is both internally and externally threaded. A cup-like member 2|(illustrated in Fig. 6) has a central aperture so that it may be droppedover the core l7, and rest upon the coating IE on the upper surface ofthe base N3 of the core. This cup-like, or flanged annular member 2|forms the bottom segment of rigid protective dielectric shield meanswhich cover the core I! to protect it from the action of acid or fromelectro-chemical reactions. The bottom segment 2| is slotted at 22, andis placed with the slot 22 alined with the slot 20 in the core.

A metal ball 23 rests in a dimple in the bottom of the core H, andfurnishes a bearing surface for a plating point 24 which may be restedin the registering slots 23 and 22. As best seen in Figs. 2 and 3, theplating point is a metal tube or rod which is covered with a dielectricjacket 25 throughout its entire area with the exception of the centralportion 26 which is in contact with the metal ball 23, and its tips 21.The dielectric jacket 25 fits snugly within the slots 23 and 22,

so that a sealing contact may be effected between the jacket 25 and thebottom segment 2| of the dielectric shield means.

A threaded plug 28 screws into the internal thread of the core I! inorder to lock the plating point 24 firmly against the metal ball 23, toprovide gripping means by which the plating point 24 is prevented fromrotating in the slots 23 and 22 when any heavy object is hung on thepoint.

A rubber washer 29 overlies the upper end of the bottom segment 2|, anda protective ring 33 surmounts the rubber washer 29. A threaded metalnut 3| screws onto the external thread of the core H and may be screwedtightly against the protective ring 33 so as to compress the rubberwasher 23 and the soft coating 25 on the plating point and effect atight seal of all the marginal junctures of the several members. Asecond washer 32 of insulating material capable of adapting its shape toany irregularities in the abutting surface of the protective ring 30 orthe cap 33 preferably is placed on top of the protec tive ring 30surrounding the nut 3|. The protective dielectric shield means iscompleted by an inverted cup-shaped cap 33 which is internally threadedfor attachment to the core by screwing onto an external thread on thenut 3|. The cap 33, together with the protective ring 30 forms the topsegment of the protective dielectric shield means.

The nut 3| is provided with a kerf 3 la on each of its surfaces. Thekerf on the lower surface is provided in case slight seepage ofelectroplating liquid should cause the cap 33 to freeze to the nut 3|.In that event, the rubber washer 32 could be cut out and a tool insertedin the lower groove 3|a so as to remove the nut 3| and the cap 33 as aunit.

Preferably the outer surface of the cap 33 is knurled to provide agripping surface for screwing the cap down tightly upon the Washer 32,and if desired a conventional retaining spring may be inserted betweenthe cap 33 and the nut 3| to lock the cap 33 in its sealed position.

It is understood, of course, that the dielectric jacket 25 on theplating point is ordinarily formed of fairly soft rubber as are theWashers 29 and 32, so that they may conform themselves to the adjacentrigid portions of the assembly in order to effect a tight seal.

The foregoing detailed description is given for clearness ofunderstanding only, and no unnecessary limitations should be understoodtherefrom, as variations will be obvious to those skilled in the art.

I claim:

1. A contact assembly to receive a plating point on an electroplatingrack, comprising: an externally threaded cylindrical metal core having abase for metal-to-metal attachment to an electroplating rack and toreceive a protective dielectric coating which also covers said rack,said core being transversely slotted to receive a dielectric jacketedmetal plating point and make electric contact with an unjacketed portionthereof; a removable, annular protective, dielectric shield bottomsegment surrounding the lower portion of the core and having a slot inregister with the transverse slot in said core, said bottom segmentbeing constructed to seal against a coating which covers said rack andthe base of said core and the slot therein being constructed to make asnug sealing fit with the dielectric jacket on a plating point; and aremovable protective dielectric shield top segment surrounding the upperportion of the core, said top segment being threaded for attachment tothe core and having a lower portion to make sealing engagement with thebottom segment and with the dielectric jacket on a plating point.

2. A contact assembly according to claim 1 wherein the lower portion ofthe top segment is a separate annular member and is held in sealingengagement by a threaded nut, and the top segment is attached to thecore by screwing onto an external thread on said nut.

3. A contact assembly according to claim 1 wherein the core is hollow,and gripping means are provided in the core to prevent twisting of aplating point in the transverse slot.

4. A contact assembly according to claim 1 wherein the metal core isinternally threaded to receive a threaded metal plug which holds aplating point firmly in the slot of the core.

5. A contact assembly to receive a plating point on an electroplatingrack, comprising: a metal core having a base for metal-to-metalattachment to an electroplating rack and to receive a protectivedielectric coating which also covers said rack, said core beingconstructed to loosely receive a transversely extending dielectricjacketed metal plating point; attaching means cooperating with said coreto grip said plating point and make electric contact between said coreand an unjacketed portion of said plating point; a removable dielectricshield bottom segment to seat upon and seal against the dielectriccoating which covers said base and said rack, said bottom segment havingan upwardly facing groove to make a snug sealing fit with a portion ofthe perimeter of the dielectric jacket on a plating point; and aremovable dielectric shield top segment capping the core and adapted toseal against said bottom segment and against the re mainder of theperimeter of the dielectric jacket on a plating point.

6. A contact assembly according to claim 5 wherein the core isexternally threaded, the shield bottom segment sits loosely upon thedielectric coating which covers the base and the rack, the shield topsegment includes a separate annular lower portion which seats on thebottom segment, a threaded metal nut screws onto the core overlying theannular lower portion of the top segment, and the upper portion of thetop segment seals against said lower portion.

7. A contact assembly according to claim 6 wherein soft dielectricwashers are interposed between the bottom segment and the lower por tionof the top segment, and between the two portions of the top segment.

8. A contact assembly to receive a plating point on an electroplatingrack, comprising: an uninsulated, metal core having a base formetalto-metal attachment to an electroplating rack and to receive aprotective dielectric coating which also covers said rack, said corebeing constructed to loosely receive a transversely extending dielectricjacketed metal plating point; attaching means cooperating with said coreto 3 grip said plating point and make electric contact between said coreand an unjacketed portion of said plating point; a removable dielectricshield bottom segment to seat upon and seal against the dielectriccoating which covers said base and said rack, said bottom segment havinga slot to make a snug sealing fit with the dielectric coating on theplating point; and a removable protective dielectric shield top segmentsurrounding the upper portion of the core, said top segment beingconstructed for attachment to the core and having a lower portion tomake sealing engagement with the bottom segment.

ELMER E. LILES.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,054,920 Lovejoy June 17, 19131,521,592 Belke Jan. 6, 1925 2,094,392 Winslow Sept. 28, 1937 2,097,324Hill Oct. 26, 1937 2,195,630 Pa-pp Apr. 2, 1940 2,439,190 Schroeder Apr.6, 1948 FOREIGN PATENTS Number Country Date 353,147 Germany May 12, 1922542,766 France May 22, 1922

